This invention relates to improvements in and relating to the process for providing markings on metal surfaces Conventional marking processes may include those of printing, punching or etching the desired markings comprising characters, symbols and/or designs on metal surfaces.
The printing process, however, represents such a substantial drawback that the printed markings are liable to be scaled off from the base metal surface, thus providing no permanently durable markings. On the other hand, when employing the punching or stamping process, the thus produced markings represent superior permanency. However, they represent no sharply marked edges which are naturally a substantial drawback, especially when marking fine designs. This drawback will become more apparent with use of harder base metal such as stainless steel.
In the case of the etching process, even if included the photo-etching one, a mass productive efficiency could be realized only with substantial difficulty.
Other highly well known similar technique such as the engraving process, including the electrolytic engraving one, represents several drawbacks, as will appear on a comparative list which is attached hereto at the end of this specification.
It is, therefore, the main object of the present invention to provide an improved marking process by which a sharply defined and highly durable marking, either of recesses or reliefs as desired, can be provided on a metal or similar base material surface in a mass productive highly efficient mode.
The process according to this invention comprises three successive basic processing steps as follows.